Isolation of epizootic hemorrhagic disease virus from sheep in western Turkey

Epizootic hemorrhagic disease (EHD) is a systemic viral infection of ruminants, especially deer, characterized by systemic blood circulation disorders and death. Data on the prevalence, clinical and pathological characteristics, and virulence of the infection in sheep are very limited in the literature. In this study, virological details of epizootic hemorrhagic disease virus (EHDV) were investigated in sheep with clinical symptoms such as high fever, edema of the head, particularly under the chin, and lesions in the mouth and nose in the Aydin province of western Turkey. The blood serum samples taken from animals with clinical symptoms were tested for the presence of specific antibodies against bluetongue virus (BTV) and EHDV using competitive ELISA (cELISA) and agar gel precipitation test (AGPT), respectively. In addition, Bluetongue Virus Antigen Capture ELISA (BTACE) kit was used to test for BTV antigens. Supernatants collected from the cell cultures with cytopathogenic effect were subjected to BTACE to test for the presence of BTV antigens. One step RT-PCR was used to examine samples for the presence of BTV and EHDV genomes. No antibodies against BTV and EHDV and no BTV antigens were detected. However, a band of 533 base pairs was detected by RT-PCR in two of the samples, confirming the presence of the EHDV genome. These findings suggest that EHDV infection could be present in sheep in the region and may be the cause of subclinical or atypical symptoms that result in difficulties in the differential diagnosis of other viral infections.